Gas dependent hysteresis in MoS$_2$ field effect transistors

TL;DR

This study investigates how different gases and electric stress influence hysteresis in MoS2 transistors, revealing controllable hysteresis linked to gas adsorption that could enable memory device applications.

Contribution

It demonstrates the correlation between gas adsorption energy and hysteresis width, and shows how pressure and gas type can control hysteresis in MoS2 transistors.

Findings

Hysteresis correlates with gas adsorption energy.

Gas pressure and type can modulate hysteresis.

Hysteresis exhibits two distinct current levels for memory applications.

Abstract

We study the effect of electric stress, gas pressure and gas type on the hysteresis in the transfer characteristics of monolayer molybdenum disulfide (MoS2) field effect transistors. The presence of defects and point vacancies in the MoS2 crystal structure facilitates the adsorption of oxygen, nitrogen, hydrogen or methane, which strongly affect the transistor electrical characteristics. Although the gas adsorption does not modify the conduction type, we demonstrate a correlation between hysteresis width and adsorption energy onto the MoS2 surface. We show that hysteresis is controllable by pressure and/or gas type. Hysteresis features two well-separated current levels, especially when gases are stably adsorbed on the channel, which can be exploited in memory devices.